Chilean mill.



J R. SEARS.

GHILEAN MILL.

Airmoulon FILED we 2a, 1913.

Patented Nov. 3, 1914.

J. R. SEARS.

CHILEAN MILL.

APPLICATION FILED AUG 2a, 1913.

1,1 15,591. Patented Nov. 3, 1914.

.Zizuerz/Zo yw 'J. R. SEARS.

GHILEAN MILL. APPLICATION FILED AUG 28, 1913.

1 1 1 5,59 l Patented Nov. 3, 19.14.

3 SHEETS-SHEET 3.

' Win eases:

UNITED STATES PATENT OFFICE.

JAMES R. SEARS, 0F OROVILLE, CALIFORNIA, ASSIGNOR OF ONE-HALF TO WALTER M.

. SMITH, OF OROVILLE, CALIFORNIA.

CHILEAN MILL.

Specification of Letters Patent.

Patented Nov. 3, 1914.

Application filed August 28, 1913. Serial No. 787,228.

To all whom it may concern:

Be it known that 1, JAMES R. SEARS, of Oroville, in the county of Butte and State of California, have invented certain new and useful Improvements in Chilean Mills, of which the following is a specification.

This invention relates toan improvement in Chilean mills and to a new principle of operation for such mills, in that means are provided whereby the crushing rolls can. be rotated in any position in which they are supported in the mill, so that the mill may be started up with the rolls free from engagement with the charge and then, while rotating, said rolls are gradually lowered into engagement with said charge.

Chilean mills, when used in crushing ores for amalgamation inside the mill, require to be cleaned u thoroughly occasionally, and this cannot e done without removing the crushing wheels or rolls and the die. As heretofore constructed, such mills had to be ractically dismantled by detaching and takmg out the parts one at a time, in order to efi'ect a thorough clean-up, and this operation consumed a large amount of time; usually two men required a whole day to per-.

form this work. v

Accordingly, one object of my invention is to provide an improved mill and method of operating the same, whereby the spider and crushing rolls can be lifted oif together bodily as one piece, and set aside. This may conveniently'be accomplished by means of a' chain hoist and overhead trolley, and a thorough clean-up effected in a short time; not more than an hourbeing usually required.

Another important feature of th i ve tion contemplates the pro-vision of means whereby the mill may be safely started up with a load in it.

In other forms of mills, when the OWeI fails, or the mill is stopped suddeny for any cause, with a load in it, 1t 15 frequently necessary to shovel out a part of the d before starting up, in order to avoidthe danger of breaking the gearing. or some other part in starting. Accordingly, a further feature of the invention contemplates the provision of means whereby the crushing rolls may be lifted off the loadand suspended above the same in such a manner that they will revolve about the central shaft of the mill when it is started up, and may then be gradually lowered into contact with the load. Thus when the mill is started up with the load 111 it the rolls are free from the load, so that there is no danger ofbreaking the gearmg or any other part of the mill.

It is well known that itrequires much more power to start a mill with a load in it, than is required to operate the mill after starting. It becomes necessary, at intervals, to start up the mill with the load in it and consequently a sufiicient supply of power must always be available to do this, otherwise, with mills as heretofore constructed, it

has been necessary to shovel out the charge.

For example, where it requires 50 H. P. to start the mill with a load in it is necessary.

to have 50 H. P. available at all times, although after starting up only from 5 to 10 H. P. are required to keepthe mill in operation. In many cases where electricity is employed the user is charged for a peak load or 50 H. P. consumption, whereas by the use of my invention it would only be necessary to have and pay for 10 H. P. Thus it will be seen that a tremendous saving in power expense is effected.

A further feature of the invention contemplates the provision of reversible screen frames and means whereby the height of the discharge through the screens may be varied while the mill is in operation, thus varying the output of the mill.

A further feature of the invention-relates to means for automatically feeding to the mill the materialwhich is to be ground.

The invention will be clearly understood from an inspection of the accompanying drawings, in which- Figure 1 shows a front elevation of an illustrative embodiment of the invention,

.Fig. 2 is a central vertical section of the mill, Fig. 3 is a plan view of the mill, Fig. 4 is a vertical section taken on the line 4-4 in Fig. 3, Fig. 5 is a plan view of the spider" and crushing rolls, with the spider head removed, Fig. 6 1s a vertical section through a screen and discharge regulating plate, and

I Fig. 7 is a fragmentary sectional perspective view showing details of the screen mount.

As illustrated in said drawings, the mill comprises a circular receptacle l0, having an annular. bottom or die-carrying plate 12, an

' upwardly flaring outer wall 14-, and an inner wall and bottom member 16. The middle of the member or plate 16 is provided with a boss 18 iniwhich a vertical shaft 20 is .journaled to rotate. This shaft is also journaled in bearings 22 mounted in a supporting beam 24, which is a part of the frame-work which a driving pulley 38 thereon.

The outer wall of the mill is extended above the flaring portion 14 by a vertical portion 40, and said flaring portion is pro- -vided with a plurality of discharge openings 42, preferably located in one-half of 4 other suitable manner.

wear of the screens.

the wall and here shown as four in number, although any desired numbermay be employed. The discharge openings 42 are provided with screens 44 carried byreversible frames 46, which are secured to the outer face of the wall 14 by'clamps 48, or in any The screen frames are made reversible so that they may be used either side up, thusincreasing the length of Means are provided by "which the height. of the discharge may be varied without stopping the mill. This is accomplished by means of blanks or plates 50 which are held between the screens 44 and the frames 46,

and provided at their lower edges with stops 52 which engage the inner edge of the lower part of the'screen frame. These stops may be in the form of angle plates riveted to the blankf'and the blades may be of various widths to obtain the desired height of dis-' charge, it being understood that all the blanks of one set are of the same width. In order to insert a blank, the clamps 48 are loosened slightly to allow the ends of the blank to be inserted between the screen and frame, then the blank is pushed downward until its stops engage the inner edge of the bottom of the frame. I

Detachably mounted on the bottom plate 12 is a ringer die 54 of hardened sleet, and this die cooperates with tires 56, also of hardened steel, mounted on wheels-or rolls 58, which are keyed to axles 60. The axles are preferably journaled in roller bearings 62, and provided with anti-friction I thrust bearings 64, all housed-in casings 66.

The casings 66 are pivotally mounted at their inner ends on pins 68 extending be-J tween each pair of arms 7 0 of a'spider 72.

A yoke 74 connects the outer ends of each pair of spider arms 76, and its upper end portion carries an ad ust1ng screw 1 6 engaging the upper endof a coiled sprmg f7 8, the lower end of which bears against the er side of the bearing casing 66, so' that the weight of thespider rests upon the axlesv 60 and is yieldingly supported thereby.

In order to enable the mill to be-operated according to my invention, the central hub or boss of the spider 72 is slidable upon the vertical shaft 20, and is provided with a keyway which receives a feather key or spline in said shaft, whereby said. shaft causes said spider to rotate but allows the latter to be raised or lowered and yet remain in driving relation with said shaft. Mounted upon the upper end of the spider 7 2 is a head 82, having a feed-hopper-84, which is provided with a plurality of feed-pipes 86, through which the ore is fed into the mill. Mounted to swivel in the upper end of the spider-head 82- is an eye-bolt 88, which is ro- Vtatably mounted in a plate secured by bolts 92 to the upper end of said spiderhead. The end of the eye-bolt is provided with a nut 94, which engages a ball-bearing 96 and clamps it against the under side of .the plate 90, so that the spider-head is free to rotate about the eye-bolt at all times. The

eye-bolt 88 is adapted to be attached to a chain hoist 98, connected to an overhead trolley 100 which travels over a track 102. By means of the chain hoist the spider and rolls may all be lifted intact bodily and suspended at any desired heigl1t,- and when raised above the mill, as shown in dotted lines in Fig. 1, it may be movedto one side by means of the trolley 100 moving over the track'102.

With this construction it will be observed that when it becomes necessary to start the mill. with a load in it, the spider and rolls are raised to free the charge from pressure, and the mill is started up. Thisrequires verylittle. power as there is no grinding pressure exerted at this time. After the increase the pressure, until finally the full I pressure is exerted upon theore or other material which is being crushed or ground in the mill. Although I prefer to use a chain hoist for accomplishing this work, I do not wish to be limited thereto, as my invention consists broadly in a new principle :ofoperationfor a mill whereby the grinding rolls can be raised or lowered to vary the pressure on the charge while the mill is running and to raise said rolls entirely .free from the charge when starting up the mill, and also in bodily lifting up and removing the spider and rolls intact from the mill to enable a clean-up to be made, that is, the crushing and feeding mechanism may be removed intact, without dismantling the mill as has heretofore been necessary and cusfeeder.

This feeder comprises a hopper 106 which discharges onto a rotary feed-plate 108,

controlled by a ratchet and pawlmechanism and gearing'llO, said mechanism being operated by an arm 112 connected by a link 11st to one end of a lever 116, said lever being provided at its otherend with an angular portion 118, which is adapted to cooperate with feed-wheels 120 journaled on studs 122 carried by the hopper 84. When the hopper 8i rotates, the feed-wheels 120 engage in succession the angular portion of the lever 116 to a greater or less extent, depending upon the height of said Wheels as determined by the extent to which the crush ing rolls 58 have been raised above the die 54. The backward .movement of the lever is regulated by means of a feed-screw 124.

.The material discharged from the rotary feed-plate 108 falls into a chute 126 by which said material is conveyed to the hopper 84, and from there to the mill through the tubes 86.

While I have illustrated and described a preferred embodiment of the invention, I am aware that many modifications can be made therein by any person skilled in the art without departing from the scope of the invention as expressed in the claims.

Therefore I do not wish to be limited to all the details of construction shown .and described, but- What I claim is -1. In a Chilean mill, the combination of a receptacle having adie, grinding rolls, means to rotate said rolls comprising a vertical shaft and a support for the rolls detacha'bly mounted in driving relation on said shaft, said support having provision whereby it may be suspended during the rotation of said rolls, substantially as described.

2. In a Chilean mill, the combination of a receptacle having a die, grinding rolls, means to rotate said rolls comprising avertical shaftand a support for the rolls slidably and removably mounted in driving relation on said shaft, said support having provision whereby it may be suspended during the rotation of said rolls, substantially as described.

3. In a Chilean mill, the combination of a receptacle having a die, grinding rolls and a support therefor, means slidably connected with said support to rotate said rolls in any position they may be caused to oc-- cupy, and means to move said rolls into and out of the receptacle, said last mentioned means being also arranged to convey said rolls away from the mill to enable the latinto the receptacle, and means operative to ter to be cleaned substantially as described.

4:. A Chilean mill comprising a receptacle having a die, grinding rolls and a support therefor,.means for raismg and lowering said support to move said rolls out of and rotate said rolls while in .a partially alevated position, whereby they may be brought into engagement with the charge while rotating, said support being detachably connected to said rotating means, sub-v stantially as described. a Y Y 5. A Chilean mill, comprising a screen, a die, a vertical shaft, means for rotating said shaft, a supporting member slidably keyed on said shaft, grinding rolls carried by said member and adapted to cooperate with said die, and means at the upper end of said supporting member whereby the entire member and rolls may be lifted up intact out of the mill to enable the latter to be cleaned, substantially as described.

6. A Chilean mill, comprising a circular receptacle, a vertical shaft, means whereby said shaft is rotated, a lower stationary grinding member, an upper rotatable member slidably keyed on said shaft and having grinding rolls journaled therein adapted to cooperate with said stationary grinding member, and means whereby said upper member may be suspended yet adapted to rotate while in suspended position, substantiallv as described.

7. A Chilean mill, comprising a circular receptacle, a die detachably mounted on the bottom of said receptacle, a vertical shaft, means whereby said shaft may be rotated, a spider slidably keyed to said shaft, grinding rolls journaled on said spider, and a swivel at the upper end of said spider, whereby said spider may be suspended 'yet rotated by said shaft with said rolls in cooperative relation with said (he, substantially as described.

8. A Chilean mill, comprising a receptacle having a plurality of openings in its side wall, a screen in each opening having a frame, and a removable plate extending across the bottom of said opening, said plate having stops arranged to engage the lower member ofsaid frame to regulate the height of the discharge through said screen, substantially as described. I

'9. The combination with a Chilean mill having rolls arranged to be raised and lowered automatically according to the charge in the mill, one or more wheels movable with said rolls, of a feeder having an operating arm extending laterally therefrom in the path of said wheels, whereby the amount. of material fed to the mill is automatically regulated according to the vertical position of said rolls, substantially as described.

10. The combination with a feeder having an operating arm extending laterally therefrom, of a grinding mill provided with grinding rolls arranged to be raised and lowered while grinding, and a plurality of wheels movable with said rolls and adapted to engage said arm to operate said feeder, substantially as described. 11. The comblnation with a Chilean mill having a vertically movable support, grind terial fed to said mill, substantially as deing rolls carried yby said suppbrt, one or' scribed. I more feed wheels carriedbynsaid support, In testimbn whereof I have afiixed my of a feeder for feeding material to the signature in e presence of two witnesses. 5 mill having an operating arm extending V R, SEARS laterally therefrom adapted to be engaged- Witnesses: by said feed wheels, the vertical positionof Amu M. Townsnm), said wheels determining the amount o f majGEoRuE- JONES. 

